Lawn mower grinding machines



Fell 1957 E. K. ROGERS ETAL 2,782,566

LAWN MOWER GRINDING MACHINES Filed April 21, 1954 5 Sheets-Sheet 1 la 17 a IN V EN TORS E 0634!? K ROGERS BY .FLOYD R. ROGERS II %,a a;

TTORN 5 Feb. 26, 1957 E. K. ROGERS ET AL 2,782,566

LAWN MOWER GRINDING MACHINES Filed April 21, 1954 5 Sheets-Sheet 2 INVENTORS EDGAR K ROGERS FLOYD R. ROGERS A TTORN YS Feb. 26, 1957 E. K. ROGERS ETAL LAWN MOWER GRINDING MACHINES 5 Sheets-Sheet 3 Filed April 21, 1.954

IN VEN TORS E 064 R K ROGERS FLOYD R. ROGERS ATTORN S Feb. 26, 1957 Filed April 21. 1954 E. K. ROGERS ET AL 66 LAWN MOWER GRINDING MACHINES 5 Sheets-Sheet 4 IN V EN TORS EDGAR K ROGERS By FLOYD 5. ROGERS A TTORN rs Feb. 26, 1957 E. K. ROGERS ETAL. 2,782,566

LAWN MOWER GRINDING MACHINES Filed April 21, 1954 5 Sheets-Sheet 5 IN VEN TORS EDGAR K ROGERS BY FLOYD R. ROGERS with the exceptirm, irisomecases ,of the tract n w ,accQ modate completely assembled hand la :7 'lawnmowee a a o wnmswef t'er blades.

.mower grinding machines, to which a be groundare easilyand safely secured an .ofthe invention grinding .inachin e liheithe ,o e shown and fdes cr' U. S. Patent .No. 2,180,911. The supporting and posin t d States Paten 2,782,566 [LAWN Mora ER GRlNDlN MA H N S Edgar K Rogei-s and Floyd R. Rogers, Lindsey, Qhio Application a t-n 2 1, .1as4, s i 1isr 424,536 @aims- F. f s

his invention relates .to lawnmower grin-ding maehines, and moreparticularlyto improvedjsuppo'rtin'g and] o sitioning means forsuch machines. W

Lawnmower grinding machines, heretofore, ,havebeen designed primarily to sharpenhand'lawnmowers' Such grinding machines could only accommodate hand lawnmowers whenthe handles and rollers and possibly the traction wheels were removed from th'eQ moWers, and .could not accommodate power Lawnmowers unless even more parts, such as the motors, were removed.

The principal object of this invention is to providean improved supporting and positioning ,assembly'for lawnmower grinding machines, whereby hand'a'nd'powe l wumowers of different sizes can .be secured and oned in themachines withont rerhoval ofparts from t Another object ofthis' inventi his to provi e proved supporting and positioning assembly for l W mower grinding machines which assembly will ,opt

Another object ofthis invention istouprovideen improved supportingand positioning assembly 'forl V i i 1313! 'd bly is easily operated. to position [the IdCvi theycan be accurately sharpened.

Another Object of this" invention is toprovidqin a lawnmower grinding machine, means for supporting a device to be groundforup and'downbodily adjustment andv for universalfpivotal adjustment abo tia plural axes, and means forfadjusting the device ,to b'e ground toward andaway from'the grinding wheel of the machine.

=These v and other objects and advantages willb apparent from thel'following'. d escrip'tion'fof' a. preferred form n t inv n, an improv d supportin and positioning assemblynisffprovided for' a lav'v in war 111 tioning assembly includes [a dovetail way grease the frame of .thegrinding machine, a dovetail slidably mounted in thefdovetailway-for locating a ideviceto'beground vertically to thetra'ckway ofthe rnachine means for slid- .ing-the dovetaihta. bracket, pivotally. atta'c 7 ed to the dove- .tail, .trockingimeansdor ,p'ivotingfthe bracket"about a .fgenerally .'hoiiaont al, axis for locating. the i device to be Igro'uhd horizontally toithe tracl way of the machine, a

"shaft op eratively connected to and cari'iedby th'braclget,

,additional rocking means forpivoting theshaft about a .,general'ly..vertic'al' axis forlocating the device tob ground irifp'arallel relationshipto' th'etrackw ay of they ma'chine, an dinieans.forj securing the deviee to be ground 'to the shaft." i

"Preferred inbodiments are illustrated in the accom- In the drawings:

2,782,566 Patented Feb. 26,

.tionary fmower cutter blade to be sha'rpenedsecured in .the machine.

' Figure ,IV is a plan view of the machine shown vin FigureIII. Figure V is a rear elevational view taken along the tline'V V of .Figure IV of that part of the improved supporting and positioning assembly seen from'that line. Figure ,VI isan end elevational view of the machine shown'in Figure III, showing aclamp used to steady hand 'Imowersiand stationary mowencutter' blades in the machine."

figure VII is a fragmentary view showinga device used in'place of the clamp shown in FignreVI wh en power 'mowers are secured'in the machine.

' l'lhe lawnmower grinding machine which is illustrated in the 'fig'ures' [above described has fourfunits, namely, a base 1, aframeZ carriedbythe'lbase, a grinding'assemlbly 3 supported.bythefranie, and animproyedsupporting andp ositioning asse bly ffwhich holds and positions a iclstofbe ground. Ihefrarne Zincludes a right sidejrame member 5and ,a lfeftlside' frame membero. 'Fijxedto 'the, top ofjthe frame 2 is a trackway7 comprising an outer railj 8 and an innerrailQQ A reciprocatory carriage 1t) is'mounted ,toslide on the rails 8 and 9 and carries amotor lland ja rnotor driven grinding wheel 12. The carriage 10 is operated to slide back and .forth on the trackway 7 by ,turninga handwheel ,13 fixed to acable drive shaft 14 j'ou rngaled in the right side frame member 5. The end 10f, the shaft 14 remote from the handwheel 13 has a v groove ,thejrearound whichlcooperateswith a shoillderbolt #15 (Figure VI) threaded throughthe right side frame ,irnernber 5 to retain the shaft. turns a drum ifi fi xed thereon which in turn winds or unyvinds' a cable 17 wound about the drum and running over pulley wheels 18 and attached tothe carriage 10. @The pulley wheels 18 arerotatably mounted one ate'ach Rotation of the' shaft 14 .end of the trackway 7 midway betweenflthe' rails' S andi9.

,riage 10' on the trackway 7.

Thus, rotation of the handwheel 13 reciprocates the c ar- The motor driven grinding wheel 12v is adjustable rbtatpivots .an anm 21 carrying the grinding wheel 12 about a pivot pin 22, and is adjustable trans'verselytothe trackw'ay 7 by turning a screw 23 by means of handwheelf24 which shifts the entire carriage 1 0 transversely to the tra kway The grinding assembly 3 and the operation thereof are described in detail in U. S. Patent No.1,2,180, 911. The

present i'nyention consist in providing animproved supporting and positioning assembly for machines of the type ;sl1 )iwn in said patent as hereinafter described.

'Iihe supporting and positioning assembly 4 of the present invention accommodates completely assembled haiid] and power lawnmowers with the exception, in some cases, of the traction wheels, as shown in Figures 1 and H. The'assembly, also, optionally accommodates'stati0nary mower cutter blades as shown in Figure III.

W "The supporting and positioning assembly 4'includes an assembly frame or dovetail way 25' comprisinga right dovetail plate 26 attached to legs of the right side frame member 5, a left dovetail plate 27 attached to legs of the left side frame member 6, and a dovetail way member 28 fixed to the front of the plates 26 and 27. A member or dovetail 29 is slidably mounted for vertical movement in the dovetail way 25. A gear bracket 30 having a pair of integrally formed cars 31 is attached to the dovetail way member 28. A worm shaft 32 having a worm 33 fixed thereon is rotatably mounted through the ears, the worm 33 being located between the ears. The end of the worm shaft 32 remote from the worm 33 is journaled in a Worm shaft bearing 34 (Figure IV) attached to the left side frame member 6 and carries an elevating crank 35 fixed thereon. The worm 33 cooperates with a worm gear 36 fixed on an end of a gear shaft 37 journaled in the gear bracket 30. The end of the gear shaft 37 remote from the worm gear 36 carries a pinion 38 cooperating with a rack 39 rigidly attached to the dovetail 29. When the elevating crank 35 is turned, the worm shaft 32 drives the worm 33 turning the worm gear 36 to rotate the gear shaft 37 which in turn drives the pinion 38 engaging the rack 39 to slide the dovetail 29 in the dovetail way 25. A rounded sheet metal gear guard 40 (Figure II) is attached to the gear bracket 30 and covers the top and sides of the gears.

The dovetail 29 is locked in position by means of a I wedge shaped in plan member or gib 41 located between the left dovetail plate 27 and the dovetail 29, as shown in Figure IV. The gib 41 extends the length of the dovetail way member 28, as shown in Figure III, and is positioned by means of a pair of gib clamp screws 42 having detachable knob heads 43. The clamp screws 42 have shoulders 44 which fit against the front of the dovetail way member 28 and threaded portions which extend beyond the shoulders 44 through the dovetail way member 28 which threaded portions are threaded into tapped holes in the gib 41. The gib clamp screws 42 pull the gib 41 against the dovetail 29 to wedge the dovetail securely in place which gib 41 can be easily released to permit the dovetail 29 to slide in the dovetail way 25 .by turning the knob heads 43.

When the dovetail 29 is moved in the dovetail way 25, a horizontal adjusting bracket 45 pivotally attached to the dovetail 29 moves up or down with the dovetail. The adjusting bracket 45 is attached to the dovetail 29 by means of a shouldered, horizontally extending pivot pin 46, the pin extending through the dovetail with the shouldered portion retaining the pin in the dovetail, and a nut 47 threaded on the pin just tight enough so that the adjusting bracket 45 can pivot or rock about the pivot pin 46. The pivot pin 46 is prevented from turning in the dovetail by means of an ordinary feather pin (not shown) in the dovetail which cooperates with a groove in the shouldered portion of the pin. When the adjusting bracket 45 is moved to its lowest position, it contacts a limit stop 48 fixed to the lower part of the right dovetail plate 26 to limit the travel of the slidable dovetail 29 to which the adjusting bracket 45 is attached.

Rocking means are provided for pivoting or rocking the adjusting bracket 45 about the pivot pin 46, i. e., about an axis generally transverse to the path of movement of the dovetail 29. The rocking means include a clamp pin 49 extending horizontally through the dovetail 29 and retained in the dovetail 29 by means of a shoulder on the pin and prevented from turning in the dovetail by means of an ordinary feather pin (not shown) in the dovetail which cooperates with a groove in the shoulder of the pin. The clamp pin 49 extends horizontally through an oblong hole in the bottom of the adjusting bracket 45 which hole is substantially larger than the clamp pin 49. The hole is oblong in the horizontal direction. A horizontal adjusting cam 50 having a handle 51 and an off-center hole through which the clamp pin 49 extends is located within a close fitting and integrally 'formed finished surfaced housing 52 at the bottom of the adjusting bracket 45. The horizontal adjusting cam 50 is held in place by means of a knob 53 threaded on the end of the clamp pin 49 remote from the shoulder of the pin in the dovetail 29. When the horizontal adjusting cam 50 is turned about the clamp pin 49, the cam contacts the close fitting surfaces of the housing 52 of the adjusting bracket 45 to tip the adjusting bracket 45 about the clamp pin 49 and rocks the adjusting bracket 45 about the pivot point formed by the pivot pin 46.

The knob 53 and the clamp pin 49 also serve as a locking means for the horizontal adjusting cam 50, since when the knob is advanced on the threaded end of the clamp pin, the horizontal adjusting cam 50, the adjusting bracket 45, and the dovetail 29 are squeezed together. Thus, the adjusting bracket 45, after it is rocked into its desired horizontal position, is locked securely in place by tightening the knob 53.

The adjusting bracket 45 carries a tube beam 54 fixed thereto to which tube beam a tube or shaft 55 is pivotally connected. The tube 55 has a pair of spaced apart tube seats 56 and 57 fixed thereto. The tube seat 57 is pivotally connected to the tube beam 54 by means of a tube pivot stud 58 which extends into a hole in the tube seat 57 and is pinned at 59 in the tube seat. The tube pivot stud 58 extends downwardly through a hole in the end of the tube beam 54 and a nut 60 threaded on the end of the tube pivot stud 58 holds the tube seat 57 in position. The nut 60 is tightened just enough so that the tube seat 57 can pivot when the tube pivot stud 58 turns in the hole. The tube 55, rigidly mounted on the tube seat 57, is, thus, pivotal about the pivot point formed by the tube pivot stud 58.

Rocking means are provided for pivoting or rocking the tube 55 about the axis of the tube pivot stud 58, i. e., about an axis generally parallel to the path of movement of the dovetail 29. The rocking means include a tube clamp stud 61 which extends into a hole in the tube seat 56 and is pinned at 62 in the tube seat. The tube clamp stud 61 extends downwardly through an oblong hole in the end of the tube beam 54. The longer axis of the oblong hole is transverse to the longitudinal axis of the tube beam 54. A vertical adjusting cam 63 having a handle 64 and having an off-center hole is positioned so that the tube' clamp stud 61 extends downwardly through the oblong hole of the tube beam 54 and then through the off-center hole of the vertical adjusting cam 63. The vertical adjusting cam 63 is located within a close fitting and integrally formed finished surfaced housing 65 (Figure VI) at the end of the tube beam 54. The vertical adjusting cam 63 is held in place by means of a knob 66 threaded on the end of the tube clamp stud 61. When the vertical adjusting cam 63 is turned about the tube clamp stud 61 and within the close fitting surfaces of the housing 65 of the tube beam 54, the tube clamp stud 61 is moved in the oblong hole of the tube beam 54. Movement of the tube clamp stud 61 moves the tube seat 56 pinned thereto which in turn moves the tube 55 fixed to the tube seat 56 and rocks the tube seat 57 also fixed to the tube 55 about the axis of the tube pivot stud 58. The tube 55 is, thus, pivotal about the axis of the tube pivot stud 58.

The knob 66 and the tube clamp stud 61 also serve as a locking means for the vertical adjusting cam 63, since when the knob is advanced on the threaded end of the tube clamp stud, the vertical adjusting cam 63, the tube beam 54, and the tube seat 56 are squeezed together. Thus, the tube 55, after it is rocked into its desired position, is locked securely in place by tightening the knob 66.

Devices to be ground are secured in the supporting and positioning assembly by means of a pair of V-shaped cradle brackets 67 slidably mounted on the tube 55 and a pair of adjustable cone pointed mower holders 68 also slidably mounted on the tube 55. An adjustable strut 69 slidably mounted on a rod 70 extending across the rear of the base 1 carries optionally a clamp 71 (Figure or. afixture 72 (Figure VII) scguged to ,i t s end for -.,er gaging,and steadying the devices to be ground.

Operation ,A ;han d lawmower 73 to besharpened is secured in -the machine as shown in Figurelf The rollerpf ,the mower is. placed in the V-shaped cradle brackets ,67 and -between'tlhe cone pointed mower holders 68, ,the rnoyver holders 68 -are moved near the ,ends .of the grower and tcgne points 74 of the mower holders ,68 are advanced by turning knobs 75 until they firmly contact the roller bracket of the mower, and the strut 69 carrying the clamp 71 is adjusted so that the clamp 71 may grasp a brace on the mower to steady the mower. No parts of the lawnmower need be removed, except, in some cases, the traction wheels.

The stationary mower cutter blade and the revolving reel of the lawnmower to be sharpened must be positioned with respect to the grinding assembly 3. The inner rail 9 of the trackway 7 is used as a reference line. For both grinding operations, there is only one setup of the supporting and positioning assembly. With the lawnmower secured in the supporting and positioning assembly, the elevating crank 35 is turned to raise or lower the dovetail 29 and with it the entire supporting and positioning assembly for locating the parts to be sharpened vertically to the reference line or inner rail 9. The parts to be ground are located horizontally to the inner rail 9 by pivoting the adjusting bracket 45 about the pivot pin 46 by means of the horizontal adjusting cam 50 and are located in parallel relationship to the inner rail 9 by pivoting the tube 55 about the axis of the tube pivot stud 58 by means of the vertical adjusting cam 63. A gauge may be used to check the position of the stationary mower cutter bar of the lawnmower along the inner rail 9 so that the mower cutter bar is parallel to the inner rail 9 and in the proper vertical and horizontal position. The device to be ground can be adjusted toward and away from the grinding wheel by turning the V- shaped cradle brackets 67 and the holders 68 on the tube 55 with a corresponding adjustment of the strut 69.

The power lawnmower 76 to be sharpened is secured in the grinding machine as shown in Figure II. No parts need be removed, except, in some cases, the traction wheels. The procedure for securing the power mower is the same as hereinbefore described in securing the hand mower, except that the fixture 72 (Figure VII) is substituted in place of the clamp 71 on the end of the strut 69. The fixture 72 is swung up under the power lawnmower to engage and steady the mower and help hold it in place on the beam 55. For both grinding the stationary mower cutter bar and the revolving reel, there is only one setup of the supporting and positioning assembly. The parts to be sharpened on the power lawnmower are located in parallel relationship and horizontally and vertically to the inner rail 9 of the trackway 7 in the same manner as hereinbefore described in positioning the hand lawnmower. The device to be ground can be adjusted toward and away from the grinding wheel in the same manner as hereinbefore described in positioning the hand lawnmower.

A stationary mower cutter blade 77 to be sharpened may be removed from a hand or power lawnmower and secured in the grinding machine as shown in Figure 111. The cone points 74 of the mower holders 68 are advanced by turning the knobs 75 until they enter tapped holes in the ends of the cutter blade 77. The tapped holes normally are used to cooperate with screws in attaching the cutter blade 77 to a lawnmower. The strut 69 is then adjusted so that the clamp 71 (Figure VI) may grasp the rear of the cutter blade 77. The cutter blade 77 is located in parallel relationship and horizontally and vertically to the inner rail 9 of the trackway 7 in the same manner as hereinbefore described in positioning the hand and power lawnmowers. The device to be ing ,wheel in the same manner as Yanaus ifisa isns .tna b made n snt ttiwls il of construction without departing from the spirit and scope of the invention.

iaads at b s lte av ti n We9 aim= 1. In a lawnmower grindinglmachiiie, in combination, a frame, a trackway fixed to the frame, a reciprocatory carriage on .the trackway,.means for.sliding the cam'age along the trackway, vasmotors-driven .grinding wheel adjustably mounted on the carriage, a dovetail way fixed to the frame, a dovetail slidably mounted in the dovetail way for locating a device to be ground vertically to the trackway, means for sliding the dovetail, a bracket pivotally attached to the dovetail, rocking means for pivoting the bracket about a generally horizontal axis for locating the device to be ground horizontally to the trackway, a shaft operatively connected to and carried by the bracket, additional rocking means for pivoting the shaft about a generally vertical axis for locating the device to be ground in parallel relationship to the trackway, and means for securing the device to be ground to the shaft.

2. In a lawnmower grinding machine, in combination, a frame, a trackway fixed to the frame, a reciprocatory carriage on the trackway, means for sliding the carriage along the trackway, a motor driven grinding wheel adjustably mounted on the carriage, a dovetail way fixed to the frame, a dovetail slidably mounted in the dovetail way for locating a device to be ground vertically to the trackway, gear means for sliding the dovetail, a bracket pivotally attached to the dovetail, a cam for pivoting the bracket about a generally horizontal axis for locating the device to be ground horizontally to the trackway, a shaft operatively connected to and carried by the bracket, 3. second cam for pivoting the shaft about a generally vertical axis for locating the device to be ground in parallel relationship to the trackway, and means for securing the device to be ground to the shaft.

3. In a lawnmower grinding machine, in combination, a base, a frame carried by the base, a trackway fixed to the frame, a reciprocatory carriage on the trackway, means for sliding the carriage along the trackway, a motor driven grinding wheel adjustably mounted on the carriage, a rod extending across .the rear of the base, a dovetail way fixed to the frame, a dovetail slidably mounted in the dovetail way for locating a device to be ground vertically to the trackway, locking means for the dovetail, gear means for sliding the dovetail, a bracket pivotally attached to the dovetail, a cam for pivoting the bracket about a generally horizontal axis for locating the device to be ground horizontally to the trackway, a second locking means for the cam, a shaft operatively connected to and carried by the bracket, 21 second cam for pivoting the shaft about a generally vertical axis for locating the device to be ground in parallel relationship to the trackway, a third locking means for the second cam, and means for securing the device to be gnound in the machine which means comprise at least one cradle bracket slidably mounted on the shaft, at least one adjustable mower holder slidably mounted on the shaft, and an adjustable strut slidably mounted on the rod.

4. A lawnmower grinding machine comprising, in combination, a frame, a trackway fixed to the frame, a reciprocatory carriage on the trackway, means for moving the carriage along the trackway, a grinding wheel adjustably mounted on the carriage, a vertically adjustable assembly carried by the frame for supporting and positioning a device to be ground, said assembly including a pivotally mounted bracket, rocking means for pivoting the bracket about a generally horizontal axis for locating the device to be ground horizontally to the trackway, a shaft operatively connected to and carried by the bracket, additional rocking means for pivoting the shaft about a generally vertical axis for locating the device to ggrsmee be ground in parallel relationship to the trackway, and

References Cited in the file of this patent UNITED STATES PATENTS Bergh Sept. 19, 1876 Holz et a]. Jan. 5, 1886 8 Winkley Feb. 28, 1893 Smith June 26, 1894 Mathieu May 26, 1903 Fetters Nov. 21, 1905 McClelland June 16, 1925 Jacobwitz Aug. 30, 1927 Rogers Nov. 21, 1939 Walling Jan. 13, 1944 Wiken et a1 Dec. 2, 1947 Anderson Dec. 16, 1947 Comstock Jan. 3, 1950, 

